Combination A/53 and A/153 receiver using a HIHO viterbi decoder

Abstract

A broadcast and receiver system for performing content from combined A / 53 and A / 153 standard transmissions enabling simultaneous reception of both signal types with one device. A combination HDTV / Mobile DTV chip can be used that does not alter the legacy HDTV forward error correction (FEC) decoder and Mobile DTV standard transmissions may include extra training signals aiding the demodulation of legacy HDTV reception. Two separate Trellis decoders can be used: one for A / 53 legacy HDTV decoding and the other for A / 153 Mobile DTV decoding that uses a Hard Input Hard Output (HIHO) type of architecture. Separate Viterbi decoders are allocated for each block of data with a block Viterbi rotator to parse out / collect results of each Viterbi decoder. Each block has its convolutional encoder reset at the beginning. The second Trellis decoder operates serially so as not to disturb the A / 53 HDTV data but could also be operated in parallel.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]Not ApplicableSTATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not ApplicableINCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC[0003]Not ApplicableNOTICE OF MATERIAL SUBJECT TO COPYRIGHT PROTECTION[0004]A portion of the material in this patent document is subject to copyright protection under the copyright laws of the United States and of other countries. The owner of the copyright rights has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the United States Patent and Trademark Office publicly available file or records, but otherwise reserves all copyright rights whatsoever. The copyright owner does not hereby waive any of its rights to have this patent document maintained in secrecy, including without limitation its rights pursuant to 37 C.F.R. §1.14.BACKGROUND OF THE INVENTION[0005]1. Field of the Invention[0006]This invention pert...

AI Technical Summary

Benefits of technology

[0017]The present invention provides a media broadcast and receiver system for the performance of content from individual or combined A / 53 and A / 153 standard transmissions. The combined system bridges the gap between terrestrial HDTV and Mobile or hand held Mobile DTV broadcasting by enabling simultaneous reception of both signal types with one device.

[0018]An aspect of the present invention is to provide a combination HDTV / Mobile DTV chip without altering the legacy HDTV forward error correction (FEC) decoder. Transmissions according to the Mobile DTV standard include extra training signals which could aid demodulation of legacy HDTV reception for those high dynamic channels. A challenge encountered with a combination receiver is that Mobile DTV has long acquisition times, thereby making prompt channel change times an issue. Therefore, a shorter latency solution would be preferred to speed up training support for HDTV service in a combination receiver.

[0019]To combat this latency, another aspect of the invention is the use of a second Trellis decoder enacting a Hard Input Hard Output (HIHO) type of architecture. This enables keeping the existing A / 53 FEC structure while only adding a post-processor for A / 153 FEC operation. A benefit of this architecture is that both A / 53 HDTV data and A / 153 Mobile DTV data can be rendered with a single chip.

[0020]More particularly, channel change time for A / 153 Mobile DTV can be quite long due to Serial Concatenated Convolutional Code (SCCC) iteration time. For some decoders, there could be eight to twelve iterations before data is available. Others have attempted to address latency issues with lower iteration counts, or by displaying graphics during channel change time. However, lower data latency can be achieved by using Trellis decoders in both the A / 53 FEC and A / 153 FEC decoders according to an aspect of the present invention. Performance may suffer somewhat with this approach, but faster channel change times will result while outputting both sets of data. For a combination A / 53 and A / 153 demodulator with large signal power, the minor bit error rate (BER) performance decrease will not be noticeable.

[0025]A further aspect of the invention is to provide a chip for semiconductor demodulators / receivers of signals with Trellis Decoders. Since convolutional codes require the symbol memory to be stored, the invention allows that memory to be altered (reset) without affecting a seamless output stream of data.

Problems solved by technology

A challenge encountered with a combination receiver is that Mobile DTV has long acquisition times, thereby making prompt channel change times an issue.

Performance may suffer somewhat with this approach, but faster channel change times will result while outputting both sets of data.

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